Across the bay from the sleek art crowd, vodka-fueled bachelorettes, and club-thumping bass lines of South Beach, Miami, lies Belle Meade, a quaint, local-leaning neighborhood that's home to Savannah Jane Buffett, eldest daughter of Jimmy, the laid-back guitar man who made us all abandon late-'70s glitter and disco for flip-flops and frozen margaritas.

"When I tell people I live in Miami, the looks on their faces are as if I told them I live in Las Vegas," Buffett says. "And I completely understand." But when she bought her three-bedroom, canal-front house six years ago, the once-seedy nabe was undergoing a shift: James Beard Award–winning Michelle Bernstein—possibly Miami's best-known chef—had just opened Michy's nearby, and the requisite Starbucks popped up on Biscayne Boulevard. Nowadays, Buffett kayaks down the canal to locavore paradise Redlight Little River, where her friend Kris Wessel cooks up New Orleans–style ribs "even when I walk in with 10 people without a reservation." She buys furniture locally, too: one-of-a-kind refurbished finds—"I want to redo my whole house with their stuff!"—from the mother-daughters staff at Found in the nearby Wynwood Art District.

Buffett grew up traveling the globe with her dad, shuffling among New York City, Palm Beach, Malibu, Aspen, St. Barts, and Nashville, but "Florida has always had a special place in my heart," she says. "When I was a kid, he used to take me out on the boat in Key West. We would fish and explore the mangroves and all the amazing wildlife. From a very early age I knew how to bait a hook, cast a line, and reel 'em in."

Now, at 32, Buffett says Miami f­inally feels like home, and it's also where she broadcasts her weekly Savannah Day Dreamin' Radio Hour SiriusXM radio show, 60 minutes of steel drum–infused pop from sunny indie artists such as Tune-Yards and Natty.

The music speaks to another infectious beachy vibe she can't shake, that of Ja­maica—she celebrated her thirtieth birthday on the island with her best friends over oysters and Red Stripe—so tonight, she's invited a dozen guests over for movie night in her backyard. (She spotted an inflatable projection screen in a SkyMall catalog a few years ago and has been throwing movie nights in the backyard ever since. Last time, she screened Spike Jonze's Where the Wild Things Are.) Tonight's showing? The 1978 cult reggae film Rockers.

"This song is so dope!" Buffett squeals as the sun sets over Belle Meade and over her friends, who are settled onto the bamboo mats, hand-embroidered Indian blankets, and lawn chairs she's set up in her sandy backyard. On-screen, Rastafarians are high-fiving, singing, and banging steel drums under a bamboo hut, and though her friends are chatting around her, Buffett is transfixed. "Whenever I spend my time in palm tree–type places, reggae seems to be the music that fits the mood best," she says, having just finished reading Timothy White's Bob Marley biography Catch a Fire—"it's hard to mess with Bob"—on her most recent trip to Jamaica. (She goes at least twice a year.) Her chill demeanor is obviously island-inspired, though it could be chalked up to genetics, too: Buffett air-dries her natural waves, sips beer from the bottle, and calls her close friends "dude" in such a lovable way that you can't help but envy her round-the-clock vacation lifestyle.

"Both [my parents] instilled in me the love of music, the spirit of adventure, and, of course, taught me how to throw a good party," she says. Her entertaining M.O. is simple—"I want the playlist to be great, I want the beer to be cold, I want to make sure there's enough food," she says, "and I want to cook it." So when the movie's over (or guests have migrated to the living room to escape the "freezing" 67-degree chill), it's time for Savvy, as her friends call her, to serve the Jamaican food she's spent the day preparing—the movie always influ­ences the menu—with the help of chef friend Adam Kanner. (Someone had to grill the jerk chicken while she mingled during the movie.) They've decided to riff off of a Jamaican menu using local farmers' market ingredients—"callaloo had just gone out of season, so we used Swiss chard for the salad," she says—and authentic fare from local grocery stores, which, in Miami, stock Jamaican bammy: a cassava flatbread that Buffett is frying and serving with the addictive peas-and-rice dish cooked in coconut milk.

As for cocktails, her friend Chris Hudnall, head bartender at the Soho Beach House, prepared his twist on a piña colada, this one served in a halved papaya—and mixed in Dad's Margaritaville-branded blender, of course.

And though it's hardly Jamaican, Buffett always serves her signature cherry tomato and cilantro salsa. "It's a staple, no matter what kind of food I'm serving," she says. "My Aunt Lulu taught me how to make it years ago, and she said you only have to give somebody credit three times before a dish is your own, but I still give her credit."

Amid the chaos of hungry guests and a roaring Marley playlist, Buffett stays cool; even when she realizes she's forgotten to make the key lime pie for dessert, she shrugs it off.

And by the time dinner's over, her guests are too absorbed in a Ring Game tournament on her back porch to care about extra helpings. To play, you hold a metal ring tied to a string hanging from the porch ceiling and swing it toward a nail stuck in a post a few feet away. The goal? Get the ring around the nail. Not as easy as it sounds; Buffett's friend Dev, a former roommate in the Belle Meade house, still can't get it after a few tries. Buffett, never one to crack under pressure, steps up to the hanging ring, lets it go, and lands it on the first try.